The present invention relates to an open-end spinning method and apparatus comprising outer and inner rotors, and specifically to a draftable open-end spinning method for a sliver formed along an inner surface of said outer rotor and apparatuses therefor.
In the so-called ring spinning method and apparatuses having been conventionally used, winding-up diameter of the yarn wound around a cop or a bobbin is varied in accordance with elevation and lowering of the ring rail, and therefore yarn spinning tension varies remarkably and periodically, thus causing nonuniformity of yarn elongation. Furthermore, yarn character becomes inferior by the friction of the traveler, and there is no further room for further improvement of the apparatus from the viewpoint of elevation of production ability or lower economy.
On the other hand, in the well-known open-end spinning method or apparatuses regarded as the method or apparatus capable of eliminating the disadvantages involved in the ring spinning method or apparatus, there is an excellent characteristic point such that a process for carrying out the roving and winding-turn of the yarn can be omitted, but the tensile strength of the spun yarn is very inferior to that of the standard yarn and excess twist is imparted to the sliver under spinning, thus causing relative narrowness of yarn use or difficulty of spinning fine yarn.
The disadvantages involved in the above-mentioned both types of the spinning method or apparatus are based on the unavoidable result caused by characters and or spinning principles of the apparatuses. Particularly, in the well-known open-end spinning apparatus, the sliver formed along the inner surface of a rotor is merely subjected to twisting while being stripped off from said inner surface and to winding-up into a package, therefore said open-end spinning apparatus is lacking in the drafting ability adapted for correcting the posture of each fiber of the sliver.